Thailand Weather Forecast

Thailand's tropical climate is governed by the Asian monsoon system, creating three distinct seasons: a hot, dry season from March to May; a warm, wet monsoon season from June to October; and a cool, dry season from November to February. The country's position in Southeast Asia means temperatures are warm year-round, but humidity and rainfall vary dramatically between seasons, shaping the rhythm of Thai life and tourism.

The mountainous north around Chiang Mai experiences cooler temperatures, particularly during the dry season when nights can drop to 10°C in highland areas. The central plains around Bangkok are flat and hot, with the monsoon season bringing frequent flooding to low-lying areas. The southern peninsular region has a different rainfall pattern, with the Gulf of Thailand coast receiving rain from October to January and the Andaman Sea coast wetter from May to October.

Bangkok is hot and humid year-round, with temperatures averaging 28-35°C and the wettest conditions from September to October. Chiang Mai in the north is cooler with more seasonal variation and occasional haze from agricultural burning in March and April. Phuket and the Andaman coast have a pronounced dry season ideal for beach tourism from November to April. Koh Samui on the Gulf side has a shifted weather pattern, with its best weather from February to September.